JP2001132987A - Air-conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air-conditioner capable of being provided with improved performance by preventing the generation of wear powder due to friction of desiccant and properly regulating a refrigerant amount both during cooling operation and during heating operation without using a separately arranged receiver tank for storing a refrigerant. SOLUTION: A main circuit 8 of a refrigerating cycle is formed by interconnecting a compressor 1, an outdoor heat-exchanger 3, and an indoor heat-exchanger 5 and the main circuit 8 is provided with a drier 7 to adsorb a moisture content in a refrigerant. In this air-conditioner, the volume of the drier 7 is set t a value not smaller than a volume in which desiccant is sealed and a space is formed in the internal part of the drier. A part of the refrigerant is stored in the space formed in the internal part of a drier.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner in which a desiccant needs to be added during a cycle in order to control the water content of a refrigerant, and in particular, uses an HFC-based refrigerant as a substitute for R22 in the field of air conditioning. Further, the present invention relates to an air conditioner in which water management after starting operation is required using a refrigerating machine oil having a high hydrolyzability such as a polyol ester.

[0002]

2. Description of the Related Art Conventionally, a refrigerant of a home air conditioner has been R2.
No. 2 is used, and mineral oil is used as the refrigerator oil. This is a system that is relatively resistant to moisture, and at present there is almost no need to add a desiccant for moisture adsorption during the cycle. However, from the viewpoint of global environmental protection, the air-conditioning refrigerant is shifting from the conventional HCFC-based R22 to the HFC-based refrigerant. Since the HFC-based refrigerant has a different polarization state of the molecule from the HCFC-based refrigerant, the refrigerating machine oil is not sufficiently dissolved in the refrigerant, and the conventional mineral oil cannot be used as the refrigerating machine oil. Therefore, it is necessary to use an artificial synthetic oil such as a polyol ester as a refrigerating machine oil having a necessary solubility. But,
In particular, polyol ester-based refrigerating machine oil has high hydrolyzability, and when there is moisture in the cycle, it reacts with the moisture to decompose into fatty acid and alcohol. This decomposition product is directly
In addition to attacking the sliding part, it further reacts to form a precipitate, which adheres in the cycle and causes clogging of the cycle.

On the other hand, the mainstream of air conditioners, particularly home air conditioners, is that an indoor unit (indoor heat exchanger) and an outdoor unit (outdoor heat exchanger) are separated and installed inside and outside a room, respectively. In general, connection work is performed using copper pipes for connection at the site, and compared to products (for example, refrigerators) that complete the cycle in factories and shipped, including water in the connection pipes The possibility of moisture entering the cycle is very high. Therefore, water management after the cycle operation is essential.

In the past, as a general method of adding a desiccant during a cycle in order to adsorb moisture in a refrigerant, a branch pipe is taken out from an appropriate part of the cycle, and a dryer filled with a desiccant is inserted at the tip of the branch pipe. By attaching it, moisture in the refrigerant is removed. An example having such a configuration is disclosed in Japanese Utility Model Laid-Open No. 59-7373. Japanese Patent Application Laid-Open No. 54-24348 discloses a device in which a detachable dryer is attached to a branch pipe and is removed after operation for an appropriate time.

[0005]

In the case of the above construction, the desiccant itself adsorbs moisture from the refrigerant accumulated in the branch part, so that the refrigerant in the branch pipe and the refrigerant circulating in the cycle are not easily exchanged. Due to the difference in water concentration near the inlet of the tube, water in the cycle will be adsorbed,
Low water adsorption speed and capacity.

On the other hand, when a desiccant is introduced into the main stream of the cycle, the desiccant body is rubbed when the gas-liquid mixed refrigerant having a high flow rate of the refrigerant passes through the desiccant, thereby generating abrasion powder. It causes clogging and abnormal wear. In the air conditioner, the flow direction of the refrigerant and the state of the gas phase / liquid phase are reversed depending on each operation state during the cooling operation or the heating operation, and therefore, the air conditioner is mounted so that the abrasion does not occur during the cooling operation. Even with a desiccant, wear occurs during the heating operation.

As a method for preventing abrasion, as described in Japanese Patent Application Laid-Open No. 54-24348, a method is considered in which a dryer is attached and then removed in an operation mode in which a liquid-phase refrigerant flows. However, it is difficult for a small home air conditioner to be reworked once it has been installed.

An object of the present invention is to prevent the generation of wear powder due to friction of a desiccant, and to properly control the amount of refrigerant during both cooling operation and heating operation without using a separate receiver tank for storing refrigerant. An object of the present invention is to provide an air conditioner that can be adjusted to improve performance.

[0009]

In order to achieve the above object, an air conditioner according to the present invention comprises a compressor, an outdoor heat exchanger, and an indoor heat exchanger connected to form a main circuit of a refrigeration cycle. In the air conditioner provided with a dryer that adsorbs moisture in the refrigerant in the main circuit, a space is formed inside the dryer by setting the volume of the dryer to a volume larger than a desiccant is sealed therein, and during a heating operation, Part of the refrigerant is stored in a space formed inside the dryer.

To achieve the above object, an air conditioner according to the present invention comprises a compressor, an outdoor heat exchanger, and an indoor heat exchanger connected to form a main circuit of a refrigeration cycle.
In an air conditioner having a gas-liquid separator for separating a gas-phase refrigerant and a liquid-phase refrigerant in the main circuit, the volume inside the gas-liquid separator is set to a volume larger than that required for gas-liquid separation. A space is formed inside the vessel, and a part of the refrigerant is stored in the space formed in the gas-liquid separator during the heating operation.

Further, in order to achieve the above object, the configuration of the air conditioner according to the present invention comprises a compressor, an outdoor heat exchanger,
An air conditioner comprising an indoor heat exchanger connected to form a main circuit of a refrigeration cycle, and a dryer for adsorbing moisture in the refrigerant and a gas-liquid separator for separating gas-phase refrigerant and liquid-phase refrigerant in the main circuit. In the above, a space is formed inside the dryer by making the volume of the dryer larger than the volume in which the desiccant is sealed, and the volume inside the gas-liquid separator is made larger than necessary for gas-liquid separation. A space is formed inside the separator, and a part of the refrigerant is stored in a space formed inside the dryer and a space formed in the gas-liquid separator during a heating operation.

Preferably, the gas-phase refrigerant separated by the gas-liquid separation device is returned to the suction side of the compressor via a gas-phase separation pressure reducing device and a check valve.

Further, in order to achieve the above object,
In the configuration of the air conditioner according to the present invention, a compressor, an outdoor heat exchanger, and an indoor heat exchanger are connected to form a main circuit of a refrigeration cycle, and a dryer and an air absorber that adsorb moisture in the refrigerant into the main circuit. An air conditioner including a gas-liquid separator for separating a phase refrigerant and a liquid-phase refrigerant, wherein the dryer and the gas-liquid separator are housed in the same container, and a container for housing the dryer and the gas-liquid separator. The volume is larger than the volume in which the desiccant is sealed, and a space is formed inside the container with more than necessary for gas-liquid separation, and during the heating operation, a part of the refrigerant is filled in the space formed in the container. It is also a pool.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a refrigeration cycle of an embodiment of an air conditioner according to the present invention, and FIG. 2 is a longitudinal sectional view of a gas-liquid separator and a dryer.

In the figure, 1 is a compressor for compressing a refrigerant, 2 is a four-way valve for switching a flow path during a cooling operation and a heating operation, 3 is an outdoor heat exchanger (as a condenser during cooling operation, (It functions as an evaporator during the heating operation.) Reference numeral 4 denotes a pressure reducing device (for example, an expansion valve). 5 is an indoor heat exchanger (acts as an evaporator during cooling operation and as a condenser during heating operation), 6 is a gas-liquid separator for separating gas-phase refrigerant and liquid-phase refrigerant, 7 is a dryer, An adsorbent (for example, synthetic zeolite) for adsorbing moisture mixed in the refrigerant is enclosed therein. These devices are sequentially connected to form a main circuit 8 of the cycle. Reference numeral 9 denotes a gas-phase separation decompression device (for example, a capillary tube), and reference numeral 10 denotes a check valve, which are connected in series so that the gas-phase portion of the gas-liquid separation device 6 and the compressor 1
Interposed between the suction side.

The operation of the air conditioner configured as described above is as follows. During the cooling operation, the refrigerant that has been compressed by the compressor 1 and flows out passes through the four-way valve 2 and enters the outdoor heat exchanger 3.
Condensed and liquefied. The liquefied refrigerant passes through the decompression device 4, passes through the gas-liquid separator 6 and the dryer 7, gradually evaporates, enters the indoor heat exchanger 5 and evaporates in earnest, and the compressor 1
Return to At this time, the refrigerant discharged from the decompression device 4 is separated into a gas-phase refrigerant (gas portion) and a liquid-phase refrigerant (liquid portion) by the gas-liquid separation device 6, and only the gas-phase refrigerant flows to the dryer 7.

As shown in FIG. 2, the gas-liquid separation device 6 separates gas and liquid according to the difference in specific gravity between the liquid-phase refrigerant and the gas-phase refrigerant. The phase refrigerant is returned from the upper part to the suction side of the compressor 1 via the decompression device 9 for gas separation and the check valve 10.

The liquid-phase refrigerant passing through the dryer 7 has a relatively low flow rate as compared with the gas-liquid mixed refrigerant, and has a stable flow, so that the influence on the operation of the desiccant can be suppressed to a small level. In addition, the desiccant can be prevented from being crushed. In addition, since most of the liquid-phase refrigerant passes through the dryer 7, the performance of adsorbing moisture can be maximized. When comparing the effect of the desiccant on the operation of the liquid-phase refrigerant and the gas-liquid mixed refrigerant, for example, when R410A is used as the refrigerant, the refrigerant circulation amount is 60 kg / h, and the evaporation pressure is 1.1 MPa, the refrigerant immediately after the pressure reducing device 4 The density of the refrigerant is about 917 kg / m ³ for a gas-liquid refrigerant having a dryness of 20%. In the case of a liquid-phase refrigerant after gas-liquid separation, it is about 1132 kg / m ³ . The flow velocity at this time is about 0.47 m / s for the liquid-phase refrigerant after gas-liquid separation in the case of a copper pipe with an inner diameter of 4.95 mm, but is about 0.58 m / s for the mixed refrigerant without gas-liquid separation. It is about 1.23 times that of the liquid-phase refrigerant after liquid separation. Therefore, passing the mixed refrigerant that is not subjected to gas-liquid separation to the dryer 7 may cause an increase in the flow rate of the refrigerant and breakage of the desiccant due to the turbulent flow of the gas-liquid mixed refrigerant. Since only the liquid-phase refrigerant gas-liquid separated passes through, the increase in the flow velocity of the refrigerant and the turbulence of the gas-liquid mixed refrigerant do not cause the generation of wear powder due to the friction of the desiccant.

Further, the gas-phase separated gas-phase refrigerant is returned to the compressor 1 via the pressure-reducing device 9 for gas-phase refrigerant separation and the check valve 10, so that the performance is improved. The reason is that the volume of the gas-liquid separated liquid-phase refrigerant is about 1/7 times the volume of the mixed refrigerant that is not gas-liquid separated, the pressure loss in the piping is reduced, and the suction pressure of the compressor 1 increases. The reason for this is that the refrigerant circulation amount increases.

The gas-liquid separator 6 and the dryer 7 are
By adjusting the internal volume, a receiver (accumulation) tank for the liquid-phase refrigerant during the heating operation can be provided. That is, in the conventional small-sized household air conditioner, when comparing the optimum refrigerant amount between the cooling operation and the heating operation, the refrigerant amount is larger during the cooling operation. This is because the outdoor heat exchanger 3 is larger than the indoor heat exchanger 5 in order to secure the evaporation performance during the heating operation. Since the outdoor heat exchanger 3 is large, the outdoor heat exchanger 3 becomes a condenser. This is because the amount of refrigerant stored in the outdoor heat exchanger 3 during the cooling operation becomes larger than the amount of refrigerant stored in the indoor heat exchanger 5 during the heating operation.

For example, in a small wall-mounted air conditioner having a cooling capacity of 2.8 kW, the volume ratio between the indoor heat exchanger 5 and the outdoor heat exchanger 3 is about 1: 2. At this time, R4
10A, when the amount of refrigerant is 1000 g, and when 50
Comparing the COP of cooling with the same capacity when g of refrigerant is added, the COP increases by about 1% with the addition of refrigerant. On the other hand, the COP during the heating operation when the amount of the refrigerant is similarly changed
Is -3%. Therefore, in this case, the performance is improved by adding 50 g of the cooling condition, and conversely, it is better that the amount of the refrigerant is small under the heating condition. In order to perform optimal operation during cooling operation or heating operation, the performance is adjusted by adjusting the amount of refrigerant during cooling operation and heating operation, and collecting excess liquid-phase refrigerant during heating operation in a part of the cycle. improves.

In this embodiment, a high-density liquid-phase refrigerant flows through the gas-liquid separator 6 and the dryer 7 during the heating operation. Therefore, by setting a space inside the dryer 7 that is equal to or larger than the sealed portion of the desiccant, and by setting the gas-liquid separation device 7 to have a space that is more than necessary for gas-liquid separation, the liquid-phase refrigerant is stored in this space. The refrigerant amount is adjusted during the cooling operation and the heating operation. By optimizing the size of the space, the amount of the refrigerant is appropriately adjusted according to the operation state.

For example, using R410A as a refrigerant,
If the condensing pressure during the heating operation is 3 MPa, and the temperature of the liquid-phase refrigerant at the outlet of the indoor heat exchanger 5 is 30 ° C., the density of the liquid-phase refrigerant is about 1.036 g / cm 3,
Assuming that the difference in the amount of refrigerant between the cooling operation and the heating operation is 50 g, a receiver tank for storing about 48 cm ³ of liquid-phase refrigerant is required. By making this function in the gas-liquid separator 6 and the dryer 7 without providing a separate receiver tank, the cycle can be simplified.

FIG. 3 is a longitudinal sectional view of another embodiment of the gas-liquid separation device and the dryer section. In the present embodiment, the gas-liquid separator and the dryer are housed in the same container to constitute a dryer integrated with the gas-liquid separator.

That is, a dryer 1 integrated with a gas-liquid separator.
Reference numeral 1 denotes a drier 11a in which a desiccant is sealed substantially below the center of the container, and a gas-liquid separator 11b is used above the center of the container. These are housed in the same container. .

With this configuration, the size can be reduced.
The cycle can be simplified. Further, also in the present embodiment, a space that is equal to or greater than the desiccant enclosing portion and a space that is equal to or greater than the space required for gas-liquid separation are set in the integrally formed container, and the liquid-phase refrigerant is stored in this space. By doing so, the amount of the refrigerant is adjusted.

[0027]

According to the present invention, the generation of abrasion powder due to the friction of the desiccant is prevented, and the refrigerant can be properly controlled both in the cooling operation and the heating operation without using a separate receiver tank for storing the refrigerant. It is possible to provide an air conditioner capable of improving the performance by controlling the amount.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a refrigeration cycle of an embodiment of an air conditioner according to the present invention.

FIG. 2 is a longitudinal sectional view of a gas-liquid separator and a dryer incorporated in the embodiment of FIG.

FIG. 3 is a longitudinal sectional view of another embodiment of a gas-liquid separation device and a dryer portion.

[Explanation of symbols]

 1: Compressor 2: Four-way valve 3: Outdoor heat exchanger 4: Decompression device (expansion valve) 5: Indoor heat exchanger 6: Gas-liquid separator 7: Dryer 8: Main circuit 9: Decompression device for gas separation (capillary) Tube) 10: Check valve 11: Dryer integrated with gas-liquid separator

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Satoshi Endo 709, Tomita, Ohira-cho, Shimotsuga-gun, Tochigi 2 Inside Hitachi Tochigi Electronics Co., Ltd. Hitachi, Ltd.

Claims (5)

[Claims] An air conditioner comprising: a compressor, an outdoor heat exchanger, and an indoor heat exchanger connected to form a main circuit of a refrigeration cycle, and the main circuit includes a dryer that adsorbs moisture in a refrigerant. An air conditioner characterized in that a volume of a dryer is set to a volume larger than a volume in which a desiccant is sealed, and a space is formed inside the dryer, and a part of the refrigerant is stored in the space formed inside the dryer during a heating operation. 2. A compressor, an outdoor heat exchanger, and an indoor heat exchanger are connected to form a main circuit of a refrigeration cycle, and the main circuit includes a gas-liquid separator for separating gas-phase refrigerant and liquid-phase refrigerant. In the air conditioner provided, the space inside the gas-liquid separator is formed to have a volume larger than that required for gas-liquid separation by making the volume inside the gas-liquid separator, and the space formed in the gas-liquid separator during the heating operation An air conditioner characterized by storing a part of the refrigerant in the air conditioner. 3. A main circuit of a refrigeration cycle is constituted by connecting a compressor, an outdoor heat exchanger and an indoor heat exchanger, and a dryer for adsorbing moisture in the refrigerant to the main circuit, a gas-phase refrigerant and a liquid-phase refrigerant. An air conditioner including a gas-liquid separator that separates the air from the air, wherein the volume of the dryer is set to a volume larger than that in which the desiccant is sealed, and a space is formed inside the dryer, and the volume inside the gas-liquid separator is air. Make a space inside the gas-liquid separator with a volume larger than that required for liquid separation, and store some refrigerant in the space formed inside the dryer and the space formed in the gas-liquid separator during heating operation. A characteristic air conditioner. 4. The method according to claim 1, wherein the gas-phase refrigerant separated by the gas-liquid separation device is returned to the suction side of the compressor via a pressure reducing device for gas-phase separation and a check valve. Any air conditioner. 5. A refrigeration cycle main circuit is constituted by connecting a compressor, an outdoor heat exchanger and an indoor heat exchanger, and a dryer for adsorbing moisture in the refrigerant to the main circuit, a gas-phase refrigerant and a liquid-phase refrigerant. An air conditioner including a gas-liquid separator that separates the dryer and the gas-liquid separator, wherein the dryer and the gas-liquid separator are housed in the same container, and the volume of the container that houses the dryer and the gas-liquid separator is filled with a desiccant. It is characterized by forming a space inside the container with a volume larger than that required, and more than necessary for gas-liquid separation, and storing a part of the refrigerant in the space formed in the container during the heating operation. Air conditioner.